Method and apparatus for aligning an aircraft with a passenger loading bridge

ABSTRACT

Disclosed is a method and system for aligning a door of an aircraft to a passenger loading bridge. A final parking position of the aircraft is defined as being immediately adjacent to a position of the passenger loading bridge, such that when the aircraft is stopped at the final parking position, the passenger loading bridge requires only a telescopic extension of less than about 1 meter to complete the alignment operation. To this end, an indicating device that works cooperatively with an aircraft-engaging end of the passenger loading bridge is provided for displaying human intelligible instructions for use by a pilot of the aircraft to guide the aircraft to the final parking position.

[0001] This application claims the benefit of U.S. ProvisionalApplication Serial No. 60/400,785 filed Aug. 5, 2002.

FIELD OF THE INVENTION

[0002] The present invention relates generally to passenger loadingbridges and more particularly to a method and apparatus for aligning anaircraft with a passenger loading bridge.

BACKGROUND OF THE INVENTION

[0003] In order to make aircraft passengers comfortable, and in order totransport them between an airport terminal building and an aircraft insuch a way that they are protected from the weather and from otherenvironmental influences, passenger loading bridges are used which canbe telescopically extended and the height of which is adjustable. Forinstance, an apron drive bridge in present day use has a plurality ofadjustable modules, including: a rotunda, a telescopic tunnel, a bubblesection, a cab, and elevating columns with wheel carriage. Of course,other types of bridges are known in the art, such as for example noseloaders and pedestal bridges.

[0004] Unfortunately, the procedure for aligning the passenger loadingbridge with a doorway of the aircraft is a time consuming operation.First, the pilot taxis the aircraft along a lead-in line to a finalparking position within the gate area. Typically, the lead-in line is aphysical marker painted onto the tarmac, and it is used for guiding theaircraft along a predetermined path so a final parking position.Additional markings in the form of stop lines, one for each type ofaircraft, are provided at predetermined positions along the lead-inline. Thus, when the nose gear of a particular type of aircraft stopsprecisely at the stop line for that type of aircraft, then the aircraftis at its final parking position. Of course, the pilot's view of thetarmac surface from the cockpit of an aircraft is limited. This isparticularly true for larger aircraft, such as a Boeing 747. Typically,therefore, the pilot relies upon instructions provided by one of a humanground marshal together with up to two “wing walkers”, and an automateddocking guidance system to follow the lead-in line. Alternatively, stopbars are located on a pole that is fixedly mounted to the groundsurface, including appropriate stop bars for each type of aircraft usingthe gate. Further alternatively, a tractor or tug is, used to tow theaircraft along the lead-in line to its final parking position.

[0005] Secondly, the passenger loading bridge is aligned with the parkedaircraft, which in the case of an apron drive bridge may involveextending the bridge by 10 to 20 meters or more. Driving the bridge overa long distance is very time consuming because often the rate at whichthe bridge is moved is limited in order to reduce the risk of collidingwith ground service vehicles or personnel, and to avoid causing seriousdamage to the aircraft in the event of a collision therewith. Manual,semi-automated and fully-automated bridge alignment systems are knownfor adjusting the position of the passenger loading bridge relative tothe parked aircraft.

[0006] Manual bridge alignment systems typically are preferred by theairlines because a trained bridge-operator is present and is able toobserve directly the movements of the bridge relative to the parkedaircraft. The bridge-operator uses a control panel located within thecab section to adjust the bridge each time an aircraft arrives.Accordingly, the probability that the bridge will collide with a parkedaircraft during an alignment operation is relatively small.Unfortunately, the time that is required to align the passenger loadingbridge with the parked aircraft is greatest with a manual alignmentsystem, which translates directly into longer turn-around times for theairlines and increased passenger inconvenience. Additional delays mayalso occur from time to time with a manual bridge alignment system, forinstance in the event that the aircraft stops at its final parkingposition before the bridge-operator arrives. It is a disadvantage of themanual bridge alignment systems that bridge-operators must be employedand trained to operate the system, which increases operating costs. Itis a further disadvantage of the manual bridge alignment systems thatoperator experience and/or caution may further limit the speed at whichthe passenger loading bridge is actually moved.

[0007] Semi-automated bridge alignment systems are also known, wherebythe bridge is moved rapidly to a preset position under the control of acomputer. WO 96/08411, filed Sep. 14 1995 in the name of Anderberg,describes a semi-automated system for controlling the movement of apassenger loading bridge. When an aircraft has landed, a centralcomputer transmits information on the type of aircraft to a localcomputer of the passenger loading bridge at an assigned gate. The localcomputer accesses a database and retrieves information on the positionsof the doors for the type of aircraft that has landed, as well asinformation on the expected final parking position for the type ofaircraft at the assigned gate. The local computer uses the retrievedinformation to determine an absolute position of the door with which thebridge is to be aligned. Accordingly, the passenger loading bridge ismoved under computer control to a position close to the determinedposition of the door, for example within 2-10 meters. Optionally, thebridge is preset to this position before the aircraft has stoppedmoving.

[0008] WO 01/34467, filed Nov. 8, 2000 also in the name of Anderberg,teaches that the above system is reliable only for movement to aposition close to the parked aircraft. Thus, the bridge has to beoperated manually during the remaining 2-10 meters of its movement. TheWO 01/34467 reference also teaches an improvement to the above system,in which electromagnetic sensors are disposed along the outboard end ofthe passenger loading bridge for transmitting a set of electromagneticpulses in different directions and for detecting electromagnetic pulsesafter reflection from an aircraft. Based on the elapsed time betweentransmitting and detecting the electromagnetic pulses in differentdirections, a profile of distance as a function of direction isobtained. From the measured distance versus direction profile and theinformation stored in the computer, it is then possible to maneuver thebridge the rest of the way from the preset position to the door of theparked aircraft. Unfortunately, when the aircraft fails to stop at theexpected final parking position, the preset position will be misalignedwith the actual position of the aircraft door, and human interventionwill be required in order to complete the alignment operation.

[0009] Other automated systems have been proposed, for instance anautomatic loading bridge which uses video cameras in the control of thebridge as described by Schoenberger et al. in U.S. Pat. No. 5,226,204.The system uses the video cameras to capture images of an aircraft towhich the bridge is to be aligned, which images are provided to acomputer for image processing. An object of the image processing is tolocate doors along the lateral surface of the aircraft facing thepassenger loading bridge. The bridge is then moved automatically in adirection toward a predetermined door of the parked aircraft.Unfortunately, the system described in U.S. Pat. No. 5,226,204 suffersfrom several disadvantages. For instance, a very sophisticated imageprocessing system is required to locate a door along the side of anaircraft from a distance of up to 15 meters or more. Factors such theweather, ambient lighting conditions and the presence of interveningground support vehicles may also become very significant over such alarge distance. Furthermore, the bridge still is required to move asignificant distance during the alignment operation, which requires afinite amount of time and poses a hazard to ground service vehicles andpersonnel.

[0010] Thus, it has been a continuing problem to provide a bridgealignment system which is capable of safely and reliably aligning apassenger loading bridge with an aircraft. In addition, there has been along-standing, unfulfilled need for a bridge alignment system whichreduces the amount of time that is required to complete each bridgealignment operation.

[0011] In view of the limitations of the prior art alignment systemsdiscussed above, it is an object of the instant invention to provide analignment system for aligning a door of an aircraft to a passengerloading bridge,

[0012] It is another object of the instant invention to provide analignment system which reduces the amount of time that is required tocomplete each bridge alignment operation.

SUMMARY OF THE INVENTION

[0013] In accordance with an aspect of the instant invention there isprovided a method for aligning a passenger loading bridge having anaircraft-engaging end to a doorway of an aircraft, comprising the stepsof: guiding the aircraft toward the aircraft-engaging end of thepassenger loading bridge; providing a human intelligible indication forindicating a parking position of the aircraft, the human intelligibleindication being dependent upon a position of the aircraft-engaging endof the passenger loading bridge, such that substantially varying theposition of the aircraft-engaging end of the passenger loading bridgeresults in a substantial variation in the parking position of theaircraft; stopping the aircraft at the parking position in dependenceupon the human intelligible indication, such that the doorway of theaircraft is substantially aligned with the aircraft-engaging end of thepassenger loading bridge; and, adjusting the passenger loading bridge tomove the aircraft-engaging end into an aircraft engaging condition.

[0014] In accordance with another embodiment of the instant inventionthere is provided a method for aligning a passenger loading bridgehaving an aircraft-engaging end to a doorway of an aircraft, comprisingthe steps of: determining a type of the aircraft; determining a desiredparking position for the determined type of the aircraft; moving theaircraft-engaging end of the passenger loading bridge to a positionadjacent to the desired parking position; guiding the aircraft towardthe aircraft-engaging end of the passenger loading bridge; providing ahuman intelligible indication for indicating the desired parkingposition of the aircraft, the human intelligible indication beingdependent upon the position of the aircraft-engaging end of thepassenger loading bridge, such that substantially varying the positionof the aircraft-engaging end of the passenger loading bridge results ina substantial variation in the parking position or the aircraft;stopping the aircraft at the desired parking position in dependence uponthe human intelligible indication, such that the doorway of the aircraftis substantially aligned with the aircraft-engaging end of the passengerloading bridge; and, adjusting the passenger loading bridge to move theaircraft-engaging end into an aircraft engaging condition.

[0015] In accordance with another embodiment of the instant inventionthere is provided a method for aligning a passenger loading bridgehaving an aircraft-engaging end to a doorway of an aircraft comprisingthe steps of: determining a type of the aircraft; selecting a desiredparking position for the determined type of the aircraft from aplurality of allowed parking positions for the determined type of theaircraft in the vicinity of the passenger loading bridge; moving theaircraft-engaging end of the passenger loading bridge to a positionimmediately adjacent to the desired parking position; guiding theaircraft toward the aircraft-engaging end of the passenger loadingbridge; providing a human intelligible indication for indicating thedesired parking position of the aircraft, the human intelligibleindication being dependent upon the position of the aircraft-engagingend of the passenger loading bridge, such that substantially varying theposition of the aircraft-engaging end of the passenger loading bridgeresults in a substantial variation in the parking position of theaircraft; stopping the aircraft at the desired parking position independence upon the human intelligible indication, such that the doorwayof the aircraft is substantially aligned with the aircraft-engaging endof the passenger loading bridge, and, adjusting the passenger loadingbridge to move the aircraft-engaging end into an aircraft engagingcondition.

[0016] In accordance with another aspect of the instant invention thereis provided a system for aligning a passenger loading bridge to adoorway of an aircraft comprising: a passenger loading bridge having anaircraft-engaging end for being aligned with the doorway of theaircraft; an alignment indicator for indicating a stopping position ofthe aircraft; a controller in electrical communication with thepassenger loading bridge and with the alignment indicator fordetermining a human intelligible indication to be displayed by thealignment indicator in dependence upon a position of theaircraft-engaging end of the passenger loading bridge, wherein thestopping position of an aircraft of a same type changes with changes inthe location of the aircraft-engaging end or the passenger loadingbridge.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Exemplary embodiments of the invention will now be described inconjunction with the following drawings, in which similar referencenumbers designate similar items:

[0018]FIG. 1 is a simplified side view of an apparatus according to afirst embodiment of the instant invention;

[0019]FIG. 2 is a simplified top view of the apparatus shown in FIG. 1;

[0020]FIG. 3 is a simplified side view of an apparatus according to asecond embodiment of the instant invention;

[0021]FIG. 4 is a simplified top view of the apparatus shown in FIG. 3;

[0022]FIG. 5a is a simplified side view of an apparatus according to athird embodiment of the instant invention;

[0023]FIG. 5b is a simplified side view of the apparatus of FIG. 5aafter the pilot has partially corrected the course of the aircraft;

[0024]FIG. 5c is a simplified side view of the apparatus of FIG. 5aafter the pilot has fully corrected the course of the aircraft;

[0025]FIG. 5d is a simplified side view of the apparatus of FIG. 5aafter the pilot has taxied the aircraft to the final parking position;

[0026]FIG. 6 is a simplified top view of an apparatus according to afourth embodiment of the instant invention;

[0027]FIG. 7 is a simplified flow diagram of a method according toinstant invention for aligning an aircraft with a passenger loadingbridge;

[0028]FIG. 8 is a simplified flow diagram of another method according tothe instant invention for aligning an aircraft with a passenger loadingbridge; and

[0029]FIG. 9 is a simplified flow diagram of another method according tothe instant invention for aligning an aircraft with a passenger loadingbridge.

DETAILED DESCRIPTION OF THE INVENTION

[0030] The following description is presented to enable a person skilledin the art to make and use the invention, and is provided in the contextof a particular application and its requirements. Various modificationsto the disclosed embodiments will be readily apparent to those skilledin the art, and the general principles defined herein may be applied toother embodiments and applications without departing from the spirit andthe scope of the invention. Thus, the present invention is not intendedto be limited to the embodiments disclosed, but is to be accorded thewidest scope consistent with the principles and features disclosedherein. For instance, the drawings and the detailed description of theinvention are presented in terms of a particular application in which anapron drive bridge is used by way of a specific example. It is to beunderstood that other types of passenger loading bridges, for instancenose loaders, pedestal bridges, radial drive bridges etc. are alsoenvisaged for use with the instant invention.

[0031] Referring to FIG. 1, shown is a simplified side view of anapparatus according to a first embodiment of the instant invention. Anaircraft 2 is shown in an aligned condition with a passenger loadingbridge 4. The passenger loading bridge 4 includes a cab 6 having abumper 8 disposed along an outboard edge of a floor member thereof. Thecab 6 is pivotally mounted to an outboard end of a passageway 12 via abubble section 10. The passageway 12 includes inner and outer passagewayelements (not shown), wherein the inner element is telescopicallyreceived within the outer element such that the length of the passageway12 is variable. Of course, each passageway element includes a leftsidewall, a right sidewall, a floor member and a ceiling member.Optionally, a number of passageway elements other than two is provided.The passageway 12 is also connected at an inboard end (not shown) to aterminal building (not shown) via a rotunda (not shown) for supportingpivotal movement of the passageway 12.

[0032] The passageway 12 is suspended near the outboard end by a frame14 for adjusting the height of the passenger loading bridge 4.Furthermore, the passenger loading bridge 4 includes a wheel carriage 16with driving wheels 18 for achieving angular displacement of thepassenger bridge as well as telescoping of the inner and outerpassageway elements to alter the length of the passageway 12.

[0033] The instant invention provides an indicating device 20 forassisting the pilot as the aircraft 2 is taxied to a final parkingposition that is adjacent to the cab 6. Of course, the passenger loadingbridge 4 is a moveable structure, such that the position of the cab 6varies with time. It is therefore a feature of the instant inventionthat the indicating device 20 is dynamic in nature. Stated differently,the use of permanent markings on the tarmac surface and/or visualguidance docking systems that are fixed in position is precluded becausethe aircraft 2 is not constrained to follow a predetermined trajectorytoward its final parking position.

[0034] Referring again to FIG. 1, the indicating device 20 includes awand 22 that is positionable at different locations relative to the cab6. For example, the wand 22 is adjustably supported using a robotic arm.The indicating device 20 is preferably mounted to an outer surface ofthe passenger loading bridge 4, for instance an outer roof surface ofthe cab 6. In use, the wand is moved to a predetermined position suchthat it is directly in front of the pilot's windshield when the aircraft2 is correctly aligned with the cab 6. To this end, a controller (notshown) is provided for controlling the motion of the robotic arm. Forexample, the controller is a computer in electrical communication with aflight information database of the airport terminal. Preferably, thecontroller is also in electrical communication with a drive mechanism(not shown) of the passenger loading bridge 4, for automaticallypositioning the cab 6.

[0035] Referring now to FIG. 2, shown is a simplified top view of theapparatus described with reference to FIG. 1. The indicating device 20includes a base 24 for mounting the robotic arm to the outer roofsurface of the cab 6. In the illustrated embodiment, the robotic armincludes a first telescopic portion 26 mounted at one end to the base24, a second telescopic portion 28 pivotally attached at one end to theother end of the first telescopic portion 26, and a third telescopicportion 30 pivotally attached at one end to the other end of the secondtelescopic portion 28. The third telescopic portion 30 terminates at thewand 22, which preferably includes a soft and/or flexible tip to avoidcausing damage to the aircraft windshield 25. Optionally, the wand 22 isilluminated and or brightly colored, so as to improve its visibilityduring operation under conditions of poor lighting and/or poor weather.Further optionally, the wand 22 includes a compact display device forproviding human intelligible signals to the pilot for making fineadjustments to the trajectory of the aircraft. For instance, the compactdisplay device is for displaying a left arrow to instruct the pilot tosteer left, and a right arrow to instruct the pilot to steer right. Sucha display is particularly advantageous during the final stages of thealignment operation.

[0036] In the illustrated embodiment of FIGS. 1 and 2, each telescopicportion of the robotic arm includes two telescoping members, onetelescoping member received within the other such that the length of thetelescopic portion is adjustable, and each pivotal attachment pointsupports rotation about a single axis of rotation. Optionally, at leastsome of the telescopic portions include a number of telescoping membersother than two, and/or at least some of the pivotal attachment pointssupport rotation about more than a single axis of rotation. Furtheroptionally, the base 24 is rotatably mounted to the outer roof surfaceof the cab 6.

[0037] Referring now to FIG. 3, shown is a simplified side view of anapparatus according to a second embodiment of the instant invention.Elements labeled with the same numerals have the same function as thoseillustrated in FIG. 1. A visual guidance docking system 32 including adisplay portion 33 and an imager 34 is slidably mounted to upper andlower tracks 36 and 38, respectively. The tracks 36, 38 are mounted toone of an outer wall surface of a terminal building (not shown) and astructure separate from the terminal building. The visual guidancedocking system 32 is moveable between first and second positions alongthe tracks 36, 38, which correspond approximately to the range of motionof the passenger loading bridge 4 in a direction parallel to the tracks36, 38. Preferably, the visual guidance docking system 32 is mounted ata predetermined height to allow pilots aboard a wide variety of aircrafttypes to have an unobstructed view of the visual guidance docking system32.

[0038] Visual guidance docking systems are known in the art. Typically,the prior art visual guidance docking systems are fixed at apredetermined position, for instance along a wall of a terminal buildingat a point that is generally aligned with a lead-in line painted ontothe tarmac. An imager captures a series of images of the aircraft duringits approach to the gate area. The images are used to determine whetheror not the aircraft is following the lead-in line and to determine thedistance remaining to an expected stop position. For instance, imageprocessing is used to compare the actual position of the aircraft nosegear to the expected stop position. A graphical display device is usedto provide instructions to the pilot. For instance, the length of avertical bar indicates distance remaining to the expected stop position,whilst a pictorial representation of an aircraft represents lateraldisplacement of the aircraft from the lead-in line. Of course, otherdisplay types are known. Accordingly, the pilot is able to park theaircraft precisely based on the directions of the visual guidancedocking system, without being able to observe directly the markings onthe tarmac.

[0039] Referring now to FIG. 4, shown is a simplified top view of theapparatus described with reference to FIG. 3. A controller (not shown)is provided for positioning the visual guidance docking system 32 at aposition along the tracks 36, 38, which corresponds to an imaginarylead-in line 40 for leading the aircraft 2 toward a final parkingposition adjacent the cab 6 of passenger loading bridge 4. In this case,the lead-in lines and stop lines are known only to the controller, andthe pilot relies entirely upon instructions from the visual guidancedocking system 32 to park the aircraft 2. Of course, the imaginarylead-in line 40 is different for each type of aircraft 2 given aparticular location of the cab 6. Furthermore, the imaginary lead-inline 40 for a particular type of aircraft 2 is different each time thelocation of the cab 6 is changed.

[0040] Optionally, the visual guidance docking system 32 is slidablymounted using a number of tracks other than two. Of course, othermethods for mounting the visual guidance docking system 32 may also beenvisaged, such as for instance using cables, adjustable arms etc.Further optionally, the display portion 33 of the visual guidancedocking system 32 is fixedly mounted within the gate area, and only theimager 34 is moveable. When the display portion 33 is fixedly mounted,then the pilot views the display portion 33 at an angle that is relatedto the approach path of the aircraft. Further optionally, the imager 34is also fixed.

[0041] Referring now to FIG. 5a, shown is a simplified side view of anapparatus according to a third embodiment of the instant invention.Elements labeled with the same numerals have the same function as thoseillustrated in FIG. 1. According to the third embodiment, the slidablevisual guidance docking system 32 is replaced by a stationary visualguidance docking system in the form of a series of lights 42 that aredisposed along an outer wall surface of a terminal building (not shown).Optionally, the lights 42 are mounted to a structure separate from theterminal building. Of course, an imager (not shown) is provided forsensing the aircraft during its approach to the gate area. For instance,the imager captures a series of images of the approaching aircraft, andthe images are used to determine whether or not the aircraft isfollowing an imaginary lead-in line to a final parking position. Forinstance, image processing is used to compare the actual position of theaircraft nose gear to the final parking position.

[0042] Preferably, the lights 42 include a plurality of individual lightsources. As shown in FIG. 5a, the individual light sources are arrangedinto three rows separated vertically one from the other. The middle rowincludes approximately twice as many individual light sources comparedto either one of the upper row and the lower row. A controller incommunication with the imager and with the passenger loading bridge isprovided for selectively illuminating the individual light sources toproduce human intelligible patterns. As shown in FIG. 5a, certainindividual light sources 44 may be caused to flash on and off toindicate, for example, the position of an imaginary aircraft centerlinefor the expected stop position. A pilot may use the flashing lightsources 44 as a beacon for steering the aircraft, especially during theearly phase of an alignment operation. Furthermore, certain otherindividual light sources may be selectively illuminated, as representedby source 46, to form a human intelligible pattern in the form of anarrow having a direction indicating head portion 48 and a distanceindicating tail portion 50. As illustrated in FIG. 5a, the arrowheadportion 48 is instructing the pilot to steer left, as the aircraft hasstrayed toward the right-hand side of the imaginary lead-in line.Furthermore, the tail portion 50 indicates that a relatively largesteering correction is required.

[0043] Referring now to FIG. 5b, shown is a simplified side view of theapparatus of FIG. 5a after the pilot has partially corrected the courseof the aircraft. Elements labeled with the same numerals have the samefunction as those illustrated in FIG. 5a. The arrowhead 48 is stillinstructing the pilot to steer left, but the length of the tail portion50 is reduced to indicate that a only a relatively small steeringcorrection is required.

[0044] Referring now to FIG. 5c, shown is a simplified side view of theapparatus of FIG. 5a after the pilot has fully corrected the course ofthe aircraft. Elements labeled with the same numerals have the samefunction as those illustrated in FIG. 5a. For example, two chevronshaped patterns of individual light sources are illuminated at equaldistances from the flashing centerline indicators 44. Such a pattern oflights instructs the pilot to continue along a present course untilinstructed to stop.

[0045] Referring now to FIG. 5d, shown is a simplified side view of theapparatus of FIG. 5a after the pilot has taxied the aircraft to thefinal parking position. Elements labeled with the same numerals have thesame function as those illustrated in FIG. 5a. For example, the flashingcenterline indicators 44 are now continuously illuminated and twoadjacent individual light sources 54 are illuminated to produce adiamond-shaped pattern to indicate that the aircraft has stopped at thecorrect parking position. Optionally, the controller causes the entirediamond-shaped pattern to flash in the event that the pilot reactsslowly to a stop instruction and overshoots the parking position.Further optionally, the imager provides information to the controllerfor adjusting the position of the passenger loading bridge to compensatefor any mis-parking of the aircraft.

[0046] Of course, other variations to the light signals are envisaged.For instance, the centerline indicators 44 could be made to flash at arate that is related to the distance remaining to the final parkingposition. As the distance to the final parking position decreases, theflash rate of the centerline indicators 44 is increased. Optionally, theindividual light sources are switchable between at least two colours.Most preferably, the individual light sources are switchable betweenthree colours. For instance, the centerline indicators 44 areilluminated in a green colour, either flashing or solid, to indicatethat a sensed speed of the aircraft is within a predetermined safe rangeof speeds. Yellow illumination of the centerline indicators 44 is usedto indicate that the aircraft is approaching the upper limit of thepredetermined safe range of speeds, and to instruct the pilot to reducethe speed of the aircraft accordingly. Furthermore, red illumination isused to instruct the pilot to bring the aircraft to an immediate halt.Of course, as the aircraft nears the passenger loading bridge, thecontroller automatically reduces the upper limit of the predeterminedsafe range of speeds, such that when the aircraft is very close to thefinal parking position, a yellow signal will be illuminated at very lowtaxiing speeds. Advantageously, the pilot will be able to stop theaircraft very quickly when the red light pattern is illuminated, sincethe aircraft is already moving very slowly when it has moved close tothe expected parking position.

[0047] Of course, the lighting arrays 42 described with reference toFIGS. 5a to 5 d are intended to be for illustrative purposes only. It isenvisaged that different numbers of rows and columns of individual lightsources could be used and that patterns other than the ones describedabove could be created. The individual light sources include lightemitting diodes (LEDs), conventional incandescent and/or fluorescentlights, etc. In addition, words or other symbols could be presented fordirecting the pilot of the aircraft.

[0048] Referring now to FIG. 6, shown is a simplified top view of anapparatus according to a fourth embodiment of the instant invention.Elements labeled with the same numerals have the same function as thoseillustrated in FIG. 4. According to the fourth embodiment, a laser lightsource 60 is mounted to an outer wall surface 62 of an airport terminalbuilding. Optionally, the laser light source 60 is mounted to a portionof the passenger loading bridge 4 or to a separate support structure(not shown). The laser light source 60 is for emitting laser light toproject human intelligible markings onto the tarmac surface, such as forinstance a non-permanent lead-in line 64, shown as a thick solid linethat is superimposed upon the imaginary centerline 40. Advantageously,the position of the non-permanent lead-in line 64 is easily changedsimply by moving the laser light source 60 to a different position independence upon a desired final parking position of the aircraft.Optionally, the laser light is emitted along a different optical pathand the laser light source 60 remains stationary. Further optionally, animager 66 is provided for sensing a position of the aircraft and forproviding a signal to a controller in dependence upon the sensedposition. The controller is for sending a signal to the laser lightsource to change the position of the non-permanent lead-in line 64.

[0049] Optionally, the laser light source 60 is used in cooperation withan apparatus according to any one of the first, second and thirdembodiments of the instant invention. For example, the laser lightsource 60 is used to project a non-permanent lead-in line for use by apilot to guide an aircraft 2 toward the passenger loading bridge 4, andthe final movements of the aircraft 2 are performed so as to positionthe wand 22 directly in front of the pilot's windshield, as wasdescribed with reference to FIGS. 1 and 2.

[0050] Referring now to FIG. 7, shown is a simplified flow diagram of amethod according to a broad aspect of the instant invention for aligningan aircraft with a passenger loading bridge. At step 100, one end of thepassenger loading bridge is positioned at a desired location. Inparticular, the passenger loading bridge is adjusted such that the cab 6is located adjacent to a desired final parking position for an aircraft.Preferably, step 100 is performed whenever it is advantageous to selecta different final parking position. For example, step 100 is performedat the beginning of every alignment operation, on a daily basis, orseveral times during a same operating day. Optionally, step 100 isperformed one time only, for instance during an initial set-up of thepassenger loading bridge, and the aircraft of a same type always stop ata same final parking position.

[0051] At step 102, the aircraft is taxied along a trajectory toward theone end of the passenger loading bridge. The trajectory is affected bythe instantaneous position of the one end of the passenger loadingbridge. Accordingly, a same type of aircraft may follow a differenttrajectory to a different final parking position to align with a samepassenger loading bridge during different alignment operations.Optionally, the aircraft is towed along the trajectory using a tractoror a tug.

[0052] At step 104 the aircraft is stopped such that a door of theaircraft is substantially aligned with the one end of the passengerloading bridge. Preferably, the aircraft stops at a position such that afinal adjustment to align the aircraft with the passenger loading bridgerequires only that the passenger loading bridge be telescopicallyextended toward the aircraft. Preferably, the passenger loading bridgerequires an adjustment in a direction toward the aircraft of between 0.5meters to 3 meters. Most preferably, the passenger loading bridgerequires a telescopic extension of less than 1 meter more than aclearance for opening the aircraft doorway.

[0053] At step 106 the passenger loading bridge is adjusted so that itis aligned with the door of the aircraft. As described above, mostpreferably, the passenger loading bridge requires only a telescopicextension of less than 1 meter more than a clearance for opening theaircraft doorway. Of course, additional horizontal and verticaladjustments, as well as angular adjustment of the cab floor member, mayalso be required to achieve an acceptable seal against the aircraftfuselage. Advantageously, the final adjustment that is performed at step106 is small compared to the adjustment performed using the prior artsystems described supra. Accordingly, the risk of colliding with groundservice vehicles and personnel is reduced compared to the prior artsystems. Furthermore, as the bridge is moving only a small distanceduring the final adjustment, it is possible to move the bridge slowlywithout unacceptably affecting the connection time. Of course, by movingthe bridge slowly compared to the prior art systems, less damage isexpected to occur in the event of a collision with the aircraft or witha ground service vehicle.

[0054] Optionally, step 104 of stopping the aircraft such that a door ofthe aircraft is substantially aligned with the one end of the passengerloading bridge includes the step of providing a human intelligibleindication for indicating a final parking position of the aircraft. Inparticular, the indication is dependant upon the position of the one endof the passenger loading bridge.

[0055] Referring now to FIG. 8, shown is a simplified flow diagram ofanother method according to the instant invention for aligning anaircraft with a passenger loading bridge. At step 110 a type of theaircraft is determined and provided to a controller of the bridgealignment system, for instance a computer in electrical communicationwith one each of an automated bridge drive system and an alignmentindicator. For example, the type of the aircraft is provided to thecontroller from a flight information database of the airport terminalbuilding. As flight plans and gate assignments are known in advance ofan aircraft actually arriving at a particular gate, this type ofinformation is generally readily available within an airportenvironment. Optionally, a human operator provides the type of theaircraft via a keypad or another data input device that is incommunication with the bridge controller. Further optionally, sensorsassociated with the bridge controller are used to image the aircraft asit approaches its assigned gate, and image processing is performed todetermine the type of the aircraft. Of course, various combinations ofthe above methods for determining the type of the aircraft may be usedin order to ensure that the aircraft is not misidentified.

[0056] Once the aircraft has been identified, a final parking positionfor the aircraft is determined at step 112. The final parking positionis determined taking into account factors such as the size andmaneuverability of the determined type of the aircraft, ground servicingrequirements of the determined type of the aircraft, and the layout ofthe apron and associated support systems. At step 114, the controllerpositions the one end of the bridge at the determined parking position.At step 116 the aircraft is taxied along a trajectory toward the one endof the passenger loading bridge. The trajectory is affected by theposition of the one end of the passenger loading bridge, such that forseparate alignment operations a same type of aircraft may follow adifferent trajectory to a different final parking position to align witha same passenger loading bridge. Optionally, the aircraft is towed alongthe trajectory using a tractor or a tug.

[0057] As the aircraft continues to taxi toward the one end of thepassenger loading bridge, the alignment indicator is used at step 118 toprovide a human intelligible indication for indicating the final parkingposition of the aircraft. In particular, the indication is dependantupon the position of the one end of the passenger loading bridge. Forinstance, the controller moves the wand 22 of FIG. 1 to a predeterminedposition relative to the one end of the passenger loading bridge for thedetermined type of the aircraft. The pilot guides the aircraft towardthe wand such that a reference point on the aircraft, for instance thecockpit windshield, closely approaches the wand. When the wand includesa compact display device, then the controller selectively illuminates orotherwise displays symbols, such as directional arrows, for providingadditional instructions to the pilot. A similar step is performed whenthe alignment indicator is provided in a different form, such as one ofthe visual guidance docking systems described with reference to FIGS. 3to 5 d.

[0058] At step 120 the aircraft is stopped such that a door to which thepassenger loading bridge is to be connected is substantially alignedwith the one end of the passenger loading bridge. Preferably, theaircraft stops at a position such that the final adjustment to align theaircraft with the passenger loading bridge requires only that thepassenger loading bridge be telescopically extended toward the aircraft.Preferably, the passenger loading bridge requires a final adjustmenttoward the aircraft of between 0.5 meters to 3 meters. Most preferably,the passenger loading bridge requires a final adjustment toward theaircraft of less than 1 meter more than a clearance for opening theaircraft doorway. Typically, the aircraft door is not within the pilot'sfield of view, and as such the pilot relies entirely upon the humanintelligible indication to stop the aircraft at the final parkingposition.

[0059] At step 122 the passenger loading bridge is adjusted so that itis aligned with the door of the aircraft. As described above, mostpreferably, the passenger loading bridge requires only a finaladjustment toward the aircraft of less than 1 meter more than aclearance for opening the aircraft doorway. Of course, additionalhorizontal vertical, as well as angular adjustment of the cab floormember may also be required to achieve a weather-tight seal against theaircraft fuselage. Advantageously, the final adjustments that areperformed at step 106 are small compared to the adjustments performedusing the prior art systems described supra. Accordingly, the risk ofcolliding with ground service vehicles and personnel is reduced comparedto the prior art systems. Furthermore, as the bridge is moving only asmall distance, it is possible to move the bridge slowly withoutadversely affecting the connection time. Of course, by moving the bridgeslowly compared to the prior art systems, less damage is expected tooccur in the event of a collision with the aircraft or a ground servicevehicle.

[0060] Referring now to FIG. 9, shown is a simplified flow diagram ofanother method according to the instant invention for aligning anaircraft with a passenger loading bridge. At step 124 a type of theaircraft is determined and provided to a controller of the bridgealignment system, such as for instance a computer in electricalcommunication with one each of an automated bridge drive system and anindicating device. For example, the type of the aircraft is provided tothe controller from a flight information database of the airportterminal building. As flight plans and gate assignments are known wellin advance of an aircraft actually arriving at a particular gate, thistype of information is generally readily available. Optionally, a humanoperator provides the type of the aircraft via a keypad or another datainput device that is in communication with the bridge controller.Further optionally, sensors associated with the bridge controller areused to image the aircraft as it approaches its assigned gate, and imageprocessing is performed to determine the type of the aircraft in time todetermine a desired final parking position for the approaching aircraft.Of course, combinations of the above methods for determining the type ofthe aircraft may be used in order to ensure that the aircraft is notmisidentified.

[0061] Once the aircraft has been identified, a desired parking positionfor the aircraft is determined at step 126. The desired parking positionfor the aircraft is selected from a plurality of allowed positions forthe determined type of the aircraft.

[0062] At step 128, the controller positions the one end of the bridgeat the determined parking position. At step 130, the aircraft is taxiedalong a trajectory toward the one end of the passenger loading bridge.The trajectory is determined by the position of the one end of thepassenger loading bridge, such that for separate alignment operations asame type of aircraft may follow a different trajectory to a differentfinal parking position to align with a same passenger loading bridge.Optionally, the aircraft is towed along the trajectory using a tractoror a tug.

[0063] As the aircraft continues to taxi toward the one end of thepassenger loading bridge, the alignment indicator is used at step 132 toprovide a human intelligible indication for indicating the final parkingposition of the aircraft. In particular, the indication is dependantupon the position of the one end of the passenger loading bridge. Forinstance, the controller moves the wand 22 of FIG. 1 to a predeterminedposition relative to the one end of the passenger loading bridge for thedetermined type of the aircraft. The pilot guides the aircraft towardthe wand such that a reference point on the aircraft, for instance thecockpit windshield, closely approaches the wand. When the wand includesa compact display device, then the controller selectively illuminates orotherwise displays symbols, such as directional arrows, for providingadditional instructions to the pilot. A similar step is performed whenthe alignment indicator is provided in a different form, such as one ofthe visual guidance docking systems described with reference to FIGS. 3to 5 d.

[0064] At step 134 the aircraft is stopped such that a door to which thepassenger loading bridge is to be connected is substantially alignedwith the one end of the passenger loading bridge. Preferably, theaircraft stops at a position such that the final adjustment to align theaircraft with the passenger loading bridge requires only that thepassenger loading bridge be telescopically extended toward the aircraft.Preferably, the passenger loading bridge requires an adjustment in adirection toward the aircraft of between 0.5 meters to 3 meters. Mostpreferably, the passenger loading bridge requires an adjustment in adirection toward the aircraft of less than 1 meter more than a clearancefor opening the aircraft doorway. Typically, the aircraft door is notwithin the pilot's field of view, and as such the pilot relies entirelyupon the human intelligible indication to stop the aircraft at the finalparking position.

[0065] At step 136, the passenger loading bridge is adjusted so that itis aligned with the door of the aircraft. As described above, mostpreferably, the passenger loading bridge requires only an adjustment ina direction toward the aircraft of less than 1 meter more than aclearance for opening the aircraft doorway. Of course, additionalhorizontal and vertical, as well as angular adjustment of the cab floormember, may also be required to achieve a weather-tight seal against theaircraft fuselage. Advantageously, the final adjustments that areperformed at step 106 are small compared to the adjustments performedusing the prior art systems described supra. Accordingly, the risk ofcolliding with ground service vehicles and personnel is reduced comparedto the prior art systems. Furthermore, as the bridge is moving only asmall distance, it is possible to move the bridge slowly withoutadversely affecting the connection time. Of course, by moving the bridgeslowly compared to the prior art systems, less damage is expected tooccur in the event of a collision with the aircraft or a ground servicevehicle.

[0066] According to the embodiments of the instant invention disclosedsupra, the final parking position of the aircraft is dictated by theposition of the aircraft-engaging end of the passenger loading bridge,and not by a series of permanent lines and markings painted onto thetarmac surface. To this end, the instant invention provides an alignmentindicator for indicating a final parking position of the aircraft, thealignment indicator working cooperatively with the aircraft-engaging endof the passenger loading bridge.

[0067] It is an advantage of the instant invention that the distancebetween the aircraft-engaging end of the passenger loading bridge andthe door of the aircraft is small after the aircraft has stopped at itsfinal parking position. Accordingly, the final connection time iscorrespondingly small. It is a further advantage of the instantinvention that a relatively simple automated or semi-automated systemmay be used to perform the final connection. For instance, it is arelatively straightforward procedure to identify the door of theaircraft and to move the bridge into alignment therewith from a distanceof approximately 0.5 meters to 3 meters, compared to starting from 10 to20 meters away. It is still a further advantage of the instant inventionthat the risk to ground crews and ground service equipment is greatlyreduced, as the passenger loading bridge moves only a relatively shortdistance, for example approximately 0.5 meters to 3 meters. It is yetanother advantage of the instant invention that aircraft of differenttypes may approach the passenger loading bridge along different virtuallead-in lines, and/or aircraft of a same type may approach the passengerloading bridge along different virtual lead-in lines. Accordingly, thepilot does not rely upon permanent markings disposed along the tarmacsurface, which are easily obscured by snow, rubbed off, etc.

[0068] Numerous other embodiments may be envisaged without departingfrom the spirit and scope of the invention.

What is claimed is:
 1. A method for aligning a passenger loading bridgehaving an aircraft-engaging end to a doorway of an aircraft, comprisingthe steps of: guiding the aircraft toward the aircraft-engaging end ofthe passenger loading bridge; providing a human intelligible indicationfor indicating a parking position of the aircraft, the humanintelligible indication being dependent upon a position of theaircraft-engaging end of the passenger loading bridge, such thatsubstantially varying the position of the aircraft-engaging end of thepassenger loading bridge results in a substantial variation in theparking position of the aircraft; stopping the aircraft at the parkingposition in dependence upon the human intelligible indication, such thatthe doorway of the aircraft is substantially aligned with theaircraft-engaging end of the passenger loading bridge; and, adjustingthe passenger loading bridge to move the aircraft-engaging end into anaircraft engaging condition.
 2. A method according to claim 1, includingthe steps of: determining a type of the aircraft; and, selecting theparking position of the aircraft based on the determined type of theaircraft, wherein a different parking position is selected for differentaircraft types.
 3. A method according to claim 2, wherein the parkingposition of the aircraft is selected from a plurality of predeterminedparking positions for a same type of aircraft at a same passengerloading bridge.
 4. A method according to claim 2, including the step ofmoving the aircraft engaging end of the passenger loading bridge to aposition adjacent to the selected parking position of the aircraft.
 5. Amethod according to claim 1, wherein the step of adjusting the passengerloading bridge to move the aircraft-engaging end into an aircraftengaging condition includes a step of extending the passenger loadingbridge a distance of between 0.5 meters and 3 meters.
 6. A methodaccording to claim 5, wherein the step of adjusting the passengerloading bridge to move the aircraft-engaging end into an aircraftengaging condition includes a step of extending the passenger loadingbridge a distance of less than 1 meter.
 7. A method for aligning apassenger loading bridge having an aircraft-engaging end to a doorway ofan aircraft, comprising the steps of: determining a type of theaircraft; determining a desired parking position for the determined typeof the aircraft; moving the aircraft-engaging end of the passengerloading bridge to a position adjacent to the desired parking position;guiding the aircraft toward the aircraft-engaging end of the passengerloading bridge; providing a human intelligible indication for indicatingthe desired parking position of the aircraft, the human intelligibleindication being dependent upon the position of the aircraft-engagingend of the passenger loading bridge, such that substantially varying theposition of the aircraft-engaging end of the passenger loading bridgeresults in a substantial variation in the parking position of theaircraft; stopping the aircraft at the desired parking position independence upon the human intelligible indication, such that the doorwayof the aircraft is substantially aligned with the aircraft-engaging endof the passenger loading bridge; and, adjusting the passenger loadingbridge to move the aircraft-engaging end into an aircraft engagingcondition.
 8. A method according to claim 7, wherein the step ofadjusting the passenger loading bridge to move the aircraft-engaging endinto an aircraft engaging condition includes a step of extending thepassenger loading bridge a distance of between 0.5 meters and 3 meters.9. A method according to claim 8, wherein the step of adjusting thepassenger loading bridge to move the aircraft-engaging end into anaircraft engaging condition includes a step of extending the passengerloading bridge a distance of less than 1 meter.
 10. A method accordingto claim 7, wherein the step of providing a human intelligibleindication for indicating the desired parking position of the aircraftincludes the steps of: displaying symbols to convey information to anoperator of the aircraft, the information for guiding the aircrafttoward the desired parking position.
 11. A method according to claim 10,wherein the symbols are displayed using a visual guidance docking systemhaving a portion that moves in dependence upon the position of theaircraft-engaging end of the passenger loading bridge.
 12. A methodaccording to claim 10, wherein the symbols are displayed using astationary visual guidance docking system having a plurality ofindividual light sources, each individual light source being selectivelyilluminable.
 13. A method according to claim 7, wherein the step ofproviding a human intelligible indication for indicating the desiredparking position of the aircraft includes the steps of: positioning anindicator relative to the aircraft-engaging end of the passenger loadingbridge, wherein the position of the indicator is indicative of thedesired parking position of the aircraft.
 14. A method according toclaim 13, wherein the indicator is a wand.
 15. A method for aligning apassenger loading bridge having an aircraft-engaging end to a doorway ofan aircraft comprising the steps of: determining a type of the aircraft;selecting a desired parking position for the determined type of theaircraft from a plurality of allowed parking positions for thedetermined type of the aircraft in the vicinity of the passenger loadingbridge; moving the aircraft-engaging end of the passenger loading bridgeto a position immediately adjacent to the desired parking position;guiding the aircraft toward the aircraft-engaging end of the passengerloading bridge; providing a human intelligible indication for indicatingthe desired parking position of the aircraft, the human intelligibleindication being dependent upon the position of the aircraft-engagingend of the passenger loading bridge, such that substantially varying theposition of the aircraft-engaging end of the passenger loading bridgeresults in a substantial variation in the parking position of theaircraft; stopping the aircraft at the desired parking position independence upon the human intelligible indication, such that the doorwayof the aircraft is substantially aligned with the aircraft-engaging endof the passenger loading bridge; and, adjusting the passenger loadingbridge to move the aircraft-engaging end into an aircraft engagingcondition.
 16. A system for aligning a passenger loading bridge to adoorway of an aircraft comprising: a passenger loading bridge having anaircraft-engaging end for being aligned with the doorway of theaircraft; an alignment indicator for indicating a stopping position ofthe aircraft; a controller in electrical communication with thepassenger loading bridge and with the alignment indicator fordetermining a human intelligible indication to be displayed by thealignment indicator in dependence upon a position of theaircraft-engaging end of the passenger loading bridge, wherein thestopping position of an aircraft of a same type changes with changes inthe location of the aircraft-engaging end of the passenger loadingbridge.
 17. A system according to claim 16, wherein the alignmentindicator is an active indicating device.
 18. A system according toclaim 17, wherein the active indicating device includes a series ofindividual light sources arranged in rows and columns for displaying thehuman intelligible indication in the form of recognizable symbols.
 19. Asystem according to claim 18, wherein each individual light source ofthe series of individual light sources comprises a light emitting diode.20. A system according to claim 17, wherein the active indicating deviceincludes a visual guidance docking system including a display portionand a sensing portion, at least one of the display portion and thesensing portion being moveable in dependence upon the aircraft-engagingend of the passenger loading bridge.
 21. A system according to claim 17,wherein the active indicating device includes a wand.
 22. A systemaccording to claim 21, including an adjustable support arm forpositioning the wand.
 23. A system according to claim 17, wherein theactive indicating device includes a laser light source for emittinglaser light to form an image for conveying information to an operator ofthe aircraft, the information for guiding the aircraft toward thestopping position.